My preferred settings to compress Sony a5100 camera XAVC video:
===============================================================
Like AVCHD video, it can provide Blu-ray quality video from my Mirrorless camera. It is progressive video with h264 codec at 60Mbps & 60FPS (you will need  very fast SD card to enable this codex on the a5100) with PCM stereo audio.
I try to compress with AV1 video & Flac audio by:

ffmpeg  -i old.MP4  -acodec flac -compression_level 8 -vcodec libsvtav1 new.mkv

Date: August 29th 2022